The interpretation of the crisis city: the city will be broken. Here it is used as a title, which is intended to arouse everyone's attention. While enjoying the convenience brought by the mobile phone, it also reminds the danger that it is stepping. There isn’t a buzzword recently: if you lose your cell phone for money and lose your SIM card to “live†(almost all accounts can be logged in with a bound cell phone number, so don’t assume that the loss is just a cell phone). This reminds you We must correctly understand the security of mobile phones. Here we try to analyze the attack and defense of mobile phone security through three aspects: SIM card, external flash memory card, and internal storage. First of all, let's take a look at how the data in the mobile phone is restored. We know that when the mobile operating system deletes a file, it only adds tag information to a specific area of ​​the file. In fact, the data area corresponding to the file has not been similarly cleared. The data recovery software uses this principle to retrieve the deleted file. Therefore, after the data in the mobile device is deleted, it can still be extracted by special tools as long as it is not covered by the subsequent data. Leakage of Information in External Flash Cards Interested people can perform data recovery extraction by using software like R-STUDIO. Recover My Files Leakage of information stored in the mobile phone This is the focus of mobile phone recovery and recovery. There are different methods for handling mobile phone functions: i. Unable to boot or functional damage to use hard means, you can get a flash memory chip by dismantling the phone, and then use a dedicated chip to read the device, the cost is to destroy the phone; Reference link Ii. The function is intact and can be extracted using software tools. Data recovery can be performed through a dedicated mobile forensic tool or civil mobile phone recovery software. Similar recovery software includes: Wondershare Dr.Fone for Android Wondershare Dr.Fone for iOS EaseUS MobiSaver for Android EaseUS MobiSaver for iOS Easy number mobile data recovery software Android version Since mobile phone leakage may have serious consequences, how do we protect the data security of mobile phones? Next, we analyze the prevention methods through three aspects: SIM card security, external flash memory card security, and on-machine storage security. SIM card security Countermeasure: PIN code protection The following explains the interpretation of the PIN part of the Mobile Internet business office: The PIN code is the password of the SIM card to prevent others from stealing your SIM card. When you enable the PIN, it means that you have added a password to your SIM card. This SIM card password has nothing to do with which phone you use. When you insert the SIM card into any mobile phone, the mobile phone screen prompts you to enter the PIN code each time you turn on the phone. If you enter the wrong PIN code (SIM card password) three times in a row, the SIM card in the phone will be Lock automatically. You can modify the PIN code by yourself (To enable or modify the PIN code, you need to set the appropriate settings on your mobile phone. For details, see the instruction manual of the mobile phone). In addition, here is an additional sentence: If you are using a Xiaomi mobile phone, you can open the “AppLock†function in the Security Center to further protect your data. At the same time open the "find phone service" in the Xiaomi cloud service, so that in case of loss, it will be positioned according to the situation. Open the lost mode and even clear the data and other operations External flash memory card security You can use WINHEX or SD Formatter 4.0 (overwrite formatting option) software to write operations to achieve data overwrite destruction, so common data recovery software will not be able to restore On-board storage information security You can first perform a cell phone factory reset operation (or perform a flash upgrade operation), and then open the phone's own camera or camera function, continuous shooting of non-objects (such as against the white wall), until the phone memory is exhausted, the purpose is to use The files are full of mobile storage space. After the above overwriting operations, you don’t need to worry about privacy data leaking. Conclusion: The advancement of science and technology has brought convenience to people. At the same time, it must also face more challenges. I hope that more readers will be able to recognize the urgency of mobile phone security through this article. At the same time, they will face it squarely and actively respond to it.